IO-375 start-up/shut down questions

[SteveHRV7]

I have an AeroSport Power IO-375 engine, no primer, dual P-Mags. I anticipate first engine start in a few weeks. My proposed start-up procedure is to first turn on the boost pump and move the mixture to full rich but I am not sure what the proper throttle procedure is. Should I crack the throttle, open it fully and then retard it prior to start, pump it etc? With fuel injection I don't believe pumping the throttle is necessary. I believe that 750 rpm is a good idle rpm per Bart at ASP.

Shut down would be to pull the throttle back, let the temps stabilize and then pull the mixture.

Any thoughts? Getting close now!

[UnPossible]

Steve - I have an IO-375 with one P-Mag and one slick Mag.... not exactly the same but close.

I've got around 50 hours on it now and below is the sequence I use for starting it when then engine is cold.

1. Throttle Full Open, Mixture Full Rich.
2. Boost pump on for just a couple of seconds until I see a decent fuel flow (3-4 gpm or so)
3. Boost Pump off
4. Throttle just cracked open and Mixture at cutoff.
5. Engage starter
6. Slowly advance mixture until engine catches
7. I leave the mixture pretty lean for ground taxi, etc.

If the engine is hot, I use the following procedure

1. No Boost Pump
2. Throttle full open, Mixture at cutoff
3. Engage starter
4. As engine starts to catch, pull back throttle and enrichen mixture.

These procedures seem to work pretty well for me.... good luck with your first engine start.

Jason

[Rupester]

If you have Precision's Silverhawk injection, be aware it will put a ton of fuel into the cylinders if you push the mixture all the way in with the boost pump on. That mechanical injection is very efficient ... it's very easy to flood it with "injudicious" use of boost pump and mixture. I did exactly that when starting my Aerosport IO-320 ... completely flooded it, and had to drain almost a pint of fuel out of the fiberglass intake box on the bottom of the engine. There was more than 1" of fuel sitting in it.

[RV10inOz]

There are many versions of start procedures that work for some people most of the time, but once you know how the fuel system works, you soon realise there is one system that works every time.

This is not my original idea either, but I will take the credit

Cold Start
WOT, FULL RICH

Boost pump, on and as soon as the pressure gets to 20PSI or more count "One Thousand Two Thousand" and pump off.

Mixture ICO.

Throttle cracked enough to give you 1200 RPM.

Crank!


Hot start, Do nothing! Crack throttle the same, crank, as soon as it coughs, run the mixture up.

AFTER START - BOTH CASES

Lean until the RPM peaks, then ever so slightly starts to fall again. Taxi like this.

Runups done same setting at 1700 or so RPM, and richen ONLY enough to keep it smooth, no more. Watch EGT's all rise on each mag, if they dont, and one falls, you will know which plug! Cycle the prop ONCE!!

Return mixture to the leanest possible again before lining up.

Line up procedure....Pump on, Mixture rich......ROLL!

If your procedures are not like this, change!

This does EVERYTHING it should.....And NOTHING it shouldn't!

This works on all IO Lycomings, totally different on TCM/CMI